The Bumpy Road Ahead

It's year 2003 and you'll read in the press that digital cinema is still taking its sweet time coming to your local theatre. According to the latest report from WHM Cinema Consulting, you can see digital cinema on 156 cinema screens worldwide today - only 0.1% of the estimated 150,000 cinema screens around the globe. This is minuscule penetration, but purposely so.

These sites are not the beginning of a rollout, but are better thought of as "test sites". To be sure, a rollout will eventually take place, but could be a few years away. Why is digital cinema taking so long to be introduced?

As one may expect, the answer to this simple question is complex. Let's look at the digital cinema business from three perspectives: the digital part, the cinema part, and the business part.

Let's start with the digital part.

With digital systems, one of the most fundamental issues is interoperability. Interoperability means that when someone sends you a string of bits, your equipment understands them and does the right thing, such as allow you to read a word processor document, or listen to digital music, or watch digital video. There are many steps in the digital cinema signal path that require interoperability: the manner in which digital content is "wrapped" or digitally "packaged" when sent by the distributor, the file formats themselves, the distribution of security keys, the processes of decryption and decompression within the exhibition booth, and the control data that accompanies image and audio for use by projectors and sound processors. Any variation in any one of these steps creates a new permutation of the final production to be managed, which will have a negative impact on interoperability. In other words, there are a lot of opportunities to misinterpret the data bits sent by the motion picture distributor.

Today, we have four different systems in place, requiring four individual mastering processes to guarantee that a digital movie can play on each system. This situation can be compared to owning four different television sets to be sure that at least one of them will receive the television show of your choice. It's understandable that the high preparation expense can prevent the release of digital movies on each of the four systems, not an unexpected consequence of non-interoperable systems. We have to recall, however, that these are to be looked upon as test sites - it's OK that they're not fully interoperable, as long as we don't allow the situation to proliferate. Regardless of interoperability problems, the test sites have proven very useful for studios, distributors, exhibitors, and equipment makers to learn the practical issues of digital cinema.

Let's move on to the cinema part. Those who have been fortunate enough to see digital cinema in action often have a range of experiences to report. Depending on where one sits in the audience, digital projection may look like film. To some, it may look better than film. Those who have been a participant in a special demonstration may have seen digital projection side-by-side with film - which may lend more insight as to the differences between digital projection and film - and there are differences. Thus, not everyone agrees that digital projection today is good enough to replace film. Exhibitors argue that it must be arguably better then film, else why bother with the expense of changing over?

The issue of what constitutes acceptable quality in digital projection has been in debate for some time. Pixel visibility and weak shadow detail are some of the more easily observed problems by untrained eyes. As with many quality-related issues, several factors affect pixel visibility, including projection technology, spatial frequency of the pixels, and seating position of the viewer. The two projection technologies often compared, Texas Instrument's DLP and JVC's D-ILA, produce very different results in terms of pixel visibility. Another factor that affects the perception of quality is visual acuity, which refers to the number of lines observed within a degree of viewing angle. Visual acuity explains why seating position is important. HDTV, for example, is designed to be viewed at a distance of at least three picture heights for an optimum viewing experience. To achieve the same visual acuity at one picture height - which is not an uncommon seating position in a cinema - a resolution of more than twice that of HDTV is required.

Other issues such as color space affect the cinematic experience. Film has a much broader color space compared to HDTV. Color space is often illustrated by means of CIE chromaticity chart, as shown in Figure 1. In the chart, the largest ring represents the human visual system (HVS). In comparison, you can see the difference in color space between HVS and HDTV (Rec 709), film, DLP Cinema projection (DMD), and a proposed future laser projector based on technology from Silicon Light Machines (SLM).

Other issues that significantly affect our perception of quality are contrast and image brightness. Contrast is most easily perceived when viewing shadow detail, but can also have a significant effect on our perception of resolution. Deep blacks, and detailed blacks, are difficult to achieve with electronic projection. Fortunately, while these problems are difficult, they can be solved. There may be differences in opinion on where we stand in regards to having acceptable solutions, but no one can deny that much progress has been made in recent years.

Now we come to the business part. Cost is certainly the most fundamental business issue. Even if the digital and cinema parts of the equation were solved, cost would remain a major obstacle. Digital projection systems can cost about five times that of a film projection system, and probably have a third the lifetime. Cost is an issue for anyone expecting ticket prices for digital cinema to remain as they are today.

Of course, there are savings to be found. The motion picture distributors will save the cost of film prints by moving to electronic distribution, which could add up to $800 million in annual expenses not incurred. Given the high cost of the equipment and the prudence of electronic distribution, it follows that a business negotiation is necessary. In the US cinema market, the vehicles for this negotiation are shaping up to be the National Association of Theatre Owners, representing the majority of exhibitors in the US, and a new group called Digital Cinema Initiatives, formed by the seven major motion picture studios. At ShoWest this year, it was announced that the legal framework for a business negotiation was put in place by these two organizations.

So it is, then, that for the first time ever, progress is now being made on all three fronts: digital, cinema, and business. We can safely say that while the road ahead may be bumpy and the digital cinema vehicle is still revving up, in time we'll all be winners.